MAX9714ETJ+T [MAXIM]
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| 型号： | MAX9714ETJ+T |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
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| 文件： | 总18页 (文件大小：507K) |
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19-3039; Rev 2; 9/04
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers
General Description
Features
♦ Filterless Class D Amplifier
The MAX9713/MAX9714 mono/stereo class D audio
power amplifiers provide class AB amplifier performance
with class D efficiency, conserving board space and
eliminating the need for a bulky heatsink. Using a class
D architecture, these devices deliver up to 6W while
offering greater than 85% efficiency. Proprietary and
patent-protected modulation and switching schemes
render the traditional class D output filter unnecessary.
♦ Unique Spread-Spectrum Mode Offers 5dB
Emissions Improvement Over Conventional
Methods
♦ Up to 85% Efficient
♦ 6W Output Power into 8Ω
♦ Low 0.07% THD+N
♦ High PSRR (76dB at 1kHz)
The MAX9713/MAX9714 offer two modulation schemes:
a fixed-frequency mode (FFM), and a spread-spectrum
mode (SSM) that reduces EMI-radiated emissions due
to the modulation frequency. The device utilizes a fully
differential architecture, a full bridged output, and com-
prehensive click-and-pop suppression.
♦ 10V to 25V Single-Supply Operation
♦ Differential Inputs Minimize Common-Mode Noise
♦ Pin-Selectable Gain Reduces Component Count
♦ Industry-Leading Integrated Click-and-Pop
Suppression
The MAX9713/MAX9714 feature high 76dB PSRR, low
0.07% THD+N, and SNR in excess of 100dB. Short-cir-
cuit and thermal-overload protection prevent the
devices from being damaged during a fault condition.
The MAX9713 is available in a 32-pin TQFN (5mm x
5mm x 0.8mm) package. The MAX9714 is available in a
32-pin TQFN (7mm x 7mm x 0.8mm) package. Both
devices are specified over the extended -40°C to
+85°C temperature range.
♦ Low Quiescent Current (18mA)
♦ Low-Power Shutdown Mode (0.2µA)
♦ Short-Circuit and Thermal-Overload Protection
♦ Available in Thermally Efficient, Space-Saving
Packages
32-Pin TQFN (5mm x 5mm x 0.8mm)–MAX9713
32-Pin TQFN (7mm x 7mm x 0.8mm)–MAX9714
Applications
High-End Notebook
Audio
Ordering Information
LCD Monitors
LCD TVs
PIN-PACKAGE
PART
TEMP RANGE
-40oC to +85oC
-40oC to +85oC
AMP
Mono
Stereo
32 TQFN-EP*
32 TQFN-EP*
MAX9713ETJ
MAX9714ETJ
Hands-Free Car
Phone Adaptors
Desktop PCs
LCD Projectors
*EP = Exposed paddle.
Block Diagrams
0.47µF
MAX9714
INL+
OUTL+
OUTL-
H-BRIDGE
0.47µF
MAX9713
INL-
0.47µF
IN+
OUT+
OUT-
H-BRIDGE
0.47µF
0.47µF
0.47µF
IN-
INR+
INR-
OUTR+
OUTR-
H-BRIDGE
Pin Configurations appear at end of data sheet.
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers
ABSOLUTE MAXIMUM RATINGS
(All voltages referenced to GND.)
Continuous Power Dissipation (T = +70°C)
MAX9713 32-Pin TQFN (derate 21.3mW/°C
A
V
to PGND, AGND.............................................................30V
DD
OUTR_, OUTL_, C1N..................................-0.3V to (V
+ 0.3V)
above +70°C)..........................................................1702.1mW
MAX9714 32-Pin TQFN (derate 33.3mW/°C
DD
C1P............................................(V
- 0.3V) to (CHOLD + 0.3V)
DD
CHOLD........................................................(V
All Other Pins to GND.............................................-0.3V to +12V
Duration of OUTR_/OUTL_
- 0.3V) to +40V
above +70°C)..........................................................2666.7mW
Junction Temperature......................................................+150°C
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
DD
Short Circuit to GND, V ......................................Continuous
DD
Continuous Input Current (V , PGND, AGND)...................1.6A
DD
Continuous Input Current (all other pins)..........................±20mA
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V
= 15V, GND = PGND = 0V, SHDN ≥ V , A = 16dB, C = C = C
= 0.47µF, C1 = 100nF, C2 = 1µF, FS1 = FS2 = GND
REG
DD
IH
V
SS
IN
(f = 330kHz), R connected between OUTL+ and OUTL- and OUTR+ and OUTR-, T = T
to T
, unless otherwise noted.
S
L
A
MIN
MAX
Typical values are at T = +25°C.) (Notes 1, 2)
A
PARAMETER
GENERAL
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Supply Voltage Range
Quiescent Current
Shutdown Current
Turn-On Time
V
Inferred from PSRR test
10
25
17.5
23
V
DD
MAX9713
MAX9714
10
18
I
R = ∞
L
mA
µA
ms
DD
I
0.2
100
50
1.5
SHDN
C
C
= 470nF
= 180nF
SS
SS
t
ON
Amplifier Output Resistance in
Shutdown
SHDN = GND
A = 13dB
150
330
kΩ
kΩ
35
30
23
20
58
48
80
65
V
A = 16dB
V
Input Impedance
Voltage Gain
R
IN
A = 19.1dB
V
39
55
A = 22.1dB
V
31
42
G1 = L, G2 = L
G1 = L, G2 = H
G1 = H, G2 = L
G1 = H, G2 = H
21.9
18.9
12.8
15.9
22.1
19.1
13
22.3
19.3
13.2
16.3
A
dB
V
16
Gain Matching
Between channels (MAX9714)
0.5
±1.6
60
%
Output Offset Voltage
Common-Mode Rejection Ratio
V
±1.3
mV
dB
OS
CMRR
f
IN
= 1kHz, input referred
V
= 10V to 25V
54
76
DD
Power-Supply Rejection Ratio
(Note 3)
PSRR
dB
W
f
f
= 1kHz
76
RIPPLE
200mV
ripple
P-P
= 20kHz
60
RIPPLE
R = 16Ω
5.5
8
THD+N = 10%,
f = 1kHz
L
Output Power
P
OUT
R = 8Ω
L
6
2
_______________________________________________________________________________________
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers
ELECTRICAL CHARACTERISTICS (continued)
(V
= 15V, GND = PGND = 0V, SHDN ≥ V , A = 16dB, C = C = C
= 0.47µF, C1 = 100nF, C2 = 1µF, FS1 = FS2 = GND
REG
DD
IH
V
SS
IN
(f = 330kHz), R connected between OUTL+ and OUTL- and OUTR+ and OUTR-, T = T
to T
, unless otherwise noted.
S
L
A
MIN
MAX
Typical values are at T = +25°C.) (Notes 1, 2)
A
PARAMETER
SYMBOL
CONDITIONS
= 1kHz, either FFM or SSM, R = 8Ω,
MIN
TYP
MAX
UNITS
Total Harmonic Distortion Plus
Noise
f
IN
P
L
THD+N
0.07
%
= 4W
OUT
FFM
SSM
FFM
SSM
94
88
BW = 22Hz to
22kHz
R = 8Ω, P
4W, f = 1kHz
=
L
OUT
Signal-to-Noise Ratio
Oscillator Frequency
SNR
dB
97
A-weighted
91
FS1 = L, FS2 = L
FS1 = L, FS2 = H
FS1 = H, FS2 = L
300
335
460
236
335
85
370
f
kHz
%
OSC
FS1 = H, FS2 = H (spread-spectrum mode)
P
P
= 5W, f = 1kHz, R = 16Ω
IN L
OUT
OUT
Efficiency
η
= 4W, f = 1kHz, R = 8Ω
75
L
DIGITAL INPUTS (SHDN, FS_, G_)
Input Thresholds
V
V
2.5
IH
IL
V
0.8
Input Leakage Current
±1
µA
Note 1: All devices are 100% production tested at +25°C. All temperature limits are guaranteed by design.
Note 2: Testing performed with a resistive load in series with an inductor to simulate an actual speaker load. For R = 8Ω, L = 68µH.
L
For R = 16Ω, L = 136µH.
L
Note 3: PSRR is specified with the amplifier inputs connected to GND through C
.
IN
_______________________________________________________________________________________
3
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers
Typical Operating Characteristics
(136µH with 16Ω, 68µH with 8Ω, part in SSM mode, unless otherwise noted.)
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY
10
1
10
1
10
1
V
A
= +20V
= 13dB
V
A
= +15V
DD
V
A
= +15V
= 13dB
DD
V
L
DD
V
L
= 13dB
V
R = 8Ω
R = 16Ω
R = 8Ω
L
P
= 100mW
OUT
P
= 100mW
OUT
P
= 4W
P
= 5W
OUT
P
= 4W
OUT
OUT
0.1
0.01
0.1
0.01
0.1
0.01
P
= 55mW
OUT
10
100
1k
10k
100k
10
100
1k
FREQUENCY (Hz)
10k
100k
10
100
1k
10k
100k
FREQUENCY (Hz)
FREQUENCY (Hz)
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. OUTPUT POWER
10
1
10
1
100
10
V
A
P
= +15V
V
A
= +20V
= 13dB
DD
V
DD
V
L
V
A
= 15V
= 13dB
DD
V
L
= 13dB
= 4W
R = 16Ω
OUT
R = 8Ω
R = 8Ω
L
1
f = 1kHz
SSM
P
= 7.5W
OUT
f = 10kHz
0.1
0.1
0.01
0.1
0.01
f = 100Hz
0.01
0.001
FFM
P
= 120mW
OUT
10
100
1k
FREQUENCY (Hz)
10k
100k
10
100
1k
FREQUENCY (Hz)
10k
100k
0
1
2
3
4
5
6
7
OUTPUT POWER (W)
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. OUTPUT POWER
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. OUTPUT POWER
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. OUTPUT POWER
100
10
100
10
100
10
V
A
= 15V
= 13dB
V
A
= 20V
DD
V
A
= 20V
= 13dB
DD
V
DD
V
= 13dB
V
R = 16Ω
L
R = 16Ω
L
R = 8Ω
L
1
1
1
f = 1kHz
f = 1kHz
f = 1kHz
0.1
0.1
0.1
f = 10kHz
f = 10kHz
f = 10kHz
f = 10kHz
f = 100Hz
f = 100Hz
0.01
0.001
0.01
0.001
0.01
0.001
f = 100Hz
0
1
2
3
4
5
6
7
0
2
4
6
8
0
5
10
15
OUTPUT POWER (W)
OUTPUT POWER (W)
OUTPUT POWER (W)
4
_______________________________________________________________________________________
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers
Typical Operating Characteristics (continued)
(136µH with 16Ω, 68µH with 8Ω, part in SSM mode, unless otherwise noted.)
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. OUTPUT POWER
EFFICIENCY vs. OUTPUT POWER
EFFICIENCY vs. OUTPUT POWER
100
10
100
90
80
70
60
50
40
30
20
10
0
100
90
80
70
60
50
40
30
20
10
0
V
A
= 15V
= 13dB
DD
V
R = 16Ω
L
R = 16Ω
L
f = 1kHz
R = 8Ω
L
R = 8Ω
L
1
Ω
R = 8
L
SSM
0.1
FFM
6
0.01
0.001
V
A
= 15V
= 13dB
V
A
= 20V
DD
DD
V
= 13dB
V
0
2
4
8
0
2
4
6
8
10
0
3
6
9
12
OUTPUT POWER (W)
OUTPUT POWER (W)
OUTPUT POWER (W)
OUTPUT POWER
vs. SUPPLY VOLTAGE
COMMON-MODE REJECTION RATIO
vs. FREQUENCY
OUTPUT POWER
vs. LOAD RESISTANCE
8
0
10
9
V
A
= 15V
= 13dB
V
A
= 15V
= 13dB
DD
V
DD
V
L
-10
-20
-30
-40
-50
-60
-70
-80
-90
7
6
5
4
3
2
1
0
R = 8Ω
THD+N = 10%
8
7
6
5
4
3
2
1
0
THD+N = 1%
A
= 13dB
V
THD+N = 10%
R = 8Ω
L
10
13
16
19
22
25
1
10
100
10
100
1k
10k
100k
SUPPLY VOLTAGE (V)
LOAD RESISTANCE (Ω)
FREQUENCY (Hz)
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
CROSSTALK vs. FREQUENCY
OUTPUT FREQUENCY SPECTRUM
0
-20
0
20
0
V
A
V
= 15V
= 13dB
OUTPUT REFERRED
A = 13dB
V
FFM MODE
DD
V
P
= 5W
OUT
-10
= 200mV
f =1kHz
RIPPLE
P-P
R = 16Ω
L
R = 8Ω
UNWEIGHTED
-20
-40
-60
-80
-100
-120
-140
L
-20
-30
-40
-50
-60
-70
-40
-60
LEFT TO RIGHT
-80
-100
-120
RIGHT TO LEFT
0.01
0.1
1
10
100
10
100
1k
FREQUENCY (Hz)
10k
100k
0
5
10
15
20
FREQUENCY (Hz)
FREQUENCY (Hz)
_______________________________________________________________________________________
5
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers
Typical Operating Characteristics (continued)
(136µH with 16Ω, 68µH with 8Ω, part in SSM mode, unless otherwise noted.)
WIDEBAND OUTPUT SPECTRUM
(FFM MODE)
OUTPUT FREQUENCY SPECTRUM
OUTPUT FREQUENCY SPECTRUM
0
20
0
20
0
SSM MODE
= 5W
SSM MODE
RBW = 10kHz
-10
-20
-30
-40
-50
-60
-70
-80
P
P
= 5W
OUT
OUT
f = 1kHz
f = 1kHz
R = 8Ω
R = 8Ω
-20
-40
-60
-80
-100
-120
-140
L
L
-20
-40
-60
-80
-100
-120
A-WEIGHTED
RBW = 10kHz
UNWEIGHTED
-90
-100
1M
10M
100M
0
5k
10k
15k
20k
0
5k
10k
15k
20k
FREQUENCY (Hz)
FREQUENCY (Hz)
FREQUENCY (Hz)
WIDEBAND OUTPUT SPECTRUM
(SSM MODE)
TURN-ON/TURN-OFF RESPONSE
MAX9713 toc23
0
C
= 180pF
SS
-10
-20
-30
-40
-50
-60
-70
-80
SHDN
5V/div
1V/div
MAX9714
OUTPUT
f = 1kHz
R = 8Ω
-90
L
-100
1M
10M
100M
20ms/div
FREQUENCY (Hz)
SHUTDOWN SUPPLY CURRENT
vs. SUPPLY VOLTAGE
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
0.35
0.30
0.25
0.20
0.15
25
20
15
10
5
0.10
0.05
0
0
10
12
14
16
18
20
10
12
14
16
18
20
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
6
_______________________________________________________________________________________
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers
Pin Description
PIN
NAME
PGND
FUNCTION
MAX9713
MAX9714
1, 2, 23, 24
1, 2, 23, 24
Power Ground
3, 4, 21, 22
3, 4, 21, 22
V
Power-Supply Input
DD
5
6
7
5
6
7
C1N
C1P
Charge-Pump Flying Capacitor Negative Terminal
Charge-Pump Flying Capacitor Positive Terminal
CHOLD
Charge-Pump Hold Capacitor. Connect a 1µF capacitor from CHOLD to V
.
DD
8, 17, 20, 25,
26, 31, 32
8
N.C.
No Connection. Not internally connected.
9
14
13
—
—
12
REG
AGND
IN-
Internal Regulator Output. Bypass with a 0.47µF capacitor to PGND.
10
11
12
13
Analog Ground
Negative Input
Positive Input
IN+
SS
Soft-Start. Connect a 0.47µF capacitor from SS to GND to enable soft-start feature.
Active-Low Shutdown. Connect SHDN to GND to disable the device. Connect to
14
11
SHDN
V
for normal operation.
DD
15
16
17
18
G1
G2
Gain-Select Input 1
Gain-Select Input 2
18
19
FS1
Frequency-Select Input 1
19
20
FS2
Frequency-Select Input 2
27, 28
29, 30
—
—
OUT-
OUT+
INL-
Negative Audio Output
—
Positive Audio Output
9
Left-Channel Negative Input
Left-Channel Positive Input
Right-Channel Negative Input
Right-Channel Positive Input
Right-Channel Negative Audio Output
Right-Channel Positive Audio Output
Left-Channel Negative Audio Output
Left-Channel Positive Audio Output
Exposed Paddle. Connect to GND.
—
10
INL+
INR-
—
15
—
16
INR+
OUTR-
OUTR+
OUTL-
OUTL+
EP
—
25, 26
27, 28
29, 30
31, 32
—
—
—
—
—
_______________________________________________________________________________________
7
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers
Detailed Description
Table 1. Operating Modes
The MAX9713/MAX9714 filterless, class D audio power
amplifiers feature several improvements to switch-
mode amplifier technology. The MAX9713 is a mono
amplifier, the MAX9714 is a stereo amplifier. These
devices offer class AB performance with class D effi-
ciency, while occupying minimal board space. A
unique filterless modulation scheme and spread-spec-
trum switching mode create a compact, flexible, low-
noise, efficient audio power amplifier. The differential
input architecture reduces common-mode noise pick-
up, and can be used without input-coupling capacitors.
The devices can also be configured as a single-ended
input amplifier.
SWITCHING MODE
(kHz)
FS1
FS2
L
L
L
H
L
335
460
H
H
236
H
335 ±7%
Spread-Spectrum Modulation (SSM) Mode
The MAX9713/MAX9714 feature a unique, patented
spread-spectrum mode that flattens the wideband
spectral components, improving EMI emissions that
may be radiated by the speaker and cables. This mode
is enabled by setting FS1 = FS2 = H. In SSM mode, the
switching frequency varies randomly by ±1.7%kHz
around the center frequency (335kHz). The modulation
scheme remains the same, but the period of the trian-
gle waveform changes from cycle to cycle. Instead of a
large amount of spectral energy present at multiples of
the switching frequency, the energy is now spread over
a bandwidth that increases with frequency. Above a
few megahertz, the wideband spectrum looks like white
noise for EMI purposes (Figure 2).
Comparators monitor the device inputs and compare
the complementary input voltages to the triangle wave-
form. The comparators trip when the input magnitude of
the triangle exceeds their corresponding input voltage.
Operating Modes
Fixed-Frequency Modulation (FFM) Mode
The MAX9713/MAX9714 feature three FFM modes with
different switching frequencies (Table 1). In FFM mode,
the frequency spectrum of the class D output consists
of the fundamental switching frequency and its associ-
ated harmonics (see the Wideband FFT graph in the
Typical Operating Characteristics). The MAX9713/
MAX9714 allow the switching frequency to be changed
by ±35%, should the frequency of one or more of the
harmonics fall in a sensitive band. This can be done at
any time and not affect audio reproduction.
Efficiency
Efficiency of a class D amplifier is attributed to the
region of operation of the output stage transistors. In a
class D amplifier, the output transistors act as current-
steering switches and consume negligible additional
power. Any power loss associated with the class D out-
put stage is mostly due to the I*R loss of the MOSFET
on-resistance, and quiescent current overhead.
The theoretical best efficiency of a linear amplifier is
78%, however that efficiency is only exhibited at peak
output powers. Under normal operating levels (typical
music reproduction levels), efficiency falls below 30%,
whereas the MAX9714 still exhibits >80% efficiencies
under the same conditions (Figure 3).
V
= 0V
IN
Shutdown
The MAX9713/MAX9714 have a shutdown mode that
reduces power consumption and extends battery life.
Driving SHDN low places the device in low-power
(0.2µA) shutdown mode. Connect SHDN to a logic high
for normal operation.
OUT-
OUT+
Click-and-Pop Suppression
The MAX9713/MAX9714 feature comprehensive click-
and-pop suppression that eliminates audible transients
on startup and shutdown. While in shutdown, the H-
bridge is pulled to GND through 300kΩ. During startup,
Figure 1. MAX9714 Outputs with No Input Signal Applied
8
_______________________________________________________________________________________
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers
Figure 2. SSM Radiated Emissions
EFFICIENCY vs. OUTPUT POWER
SS
100
GPIO
MUTE SIGNAL
0.18µF
MAX9714
90
80
70
60
50
40
30
20
10
0
MAX9713/
MAX9714
Figure 4. MAX9713/MAX9714 Mute Circuit
CLASS AB
using a MOSFET pulldown (Figure 4). Driving SS to
GND during the power-up/down or shutdown/turn-on
cycle optimizes click-and-pop suppression.
V
= 15V
DD
f = 1kHz
R = 16Ω
L
0
2
4
6
Applications Information
OUTPUT POWER (W)
Filterless Operation
Traditional class D amplifiers require an output filter to
recover the audio signal from the amplifier’s PWM out-
put. The filters add cost, increase the solution size of
the amplifier, and can decrease efficiency. The tradi-
tional PWM scheme uses large differential output
Figure 3. MAX9714 Efficiency vs. Class AB Efficiency
or power-up, the input amplifiers are muted and an
internal loop sets the modulator bias voltages to the
correct levels, preventing clicks and pops when the H-
bridge is subsequently enabled. Following startup, a
soft-start function gradually un-mutes the input ampli-
fiers. The value of the soft-start capacitor has an impact
swings (2 ♦ V
DD
peak-to-peak) and causes large ripple
currents. Any parasitic resistance in the filter compo-
nents results in a loss of power, lowering the efficiency.
The MAX9713/MAX9714 do not require an output filter.
The devices rely on the inherent inductance of the
speaker coil and the natural filtering of both the speak-
er and the human ear to recover the audio component
of the square-wave output. Eliminating the output filter
results in a smaller, less costly, more efficient solution.
on the click/pop levels. For optimum performance, C
should be at least 180nF.
SS
Mute Function
The MAX9713/MAX9714 feature a clickless/popless
mute mode. When the device is muted, the outputs
stop switching, muting the speaker. Mute only affects
the output state, and does not shut down the device. To
mute the MAX9713/MAX9714, drive SS to GND by
Because the frequency of the MAX9713/MAX9714 out-
put is well beyond the bandwidth of most speakers,
voice coil movement due to the square-wave frequency
_______________________________________________________________________________________
9
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers
Table 2. Gain Settings
0.47µF
SINGLE-ENDED
AUDIO INPUT
IN+
IN-
P
OUT
DIFF INPUT
(V
GAIN (dB)
R (Ω)
L
at 10%
THD+N (W)
)
MAX9713/
MAX9714
RMS
0.47µF
13.0
16.1
19.1
22.1
13.0
16.1
19.1
22.1
1.27
0.89
0.63
0.45
0.78
0.54
0.39
0.27
16
16
16
16
8
8
8
8
8
6
6
6
6
Figure 5. Single-Ended Input
difference of the two inputs, any signal common to both
inputs is canceled.
8
8
Single-Ended Input
The MAX9713/MAX9714 can be configured as single-
ended input amplifiers by capacitively coupling either
input to GND and driving the other input (Figure 5).
8
is very small. Although this movement is small, a speak-
er not designed to handle the additional power can be
damaged. For optimum results, use a speaker with a
series inductance > 30µH. Typical 8Ω speakers exhibit
series inductances in the range of 30µH to 100µH.
Optimum efficiency is achieved with speaker induc-
tances > 60µH.
Component Selection
Input Filter
An input capacitor, C , in conjunction with the input
IN
impedance of the MAX9713/MAX9714, forms a high-
pass filter that removes the DC bias from an incoming
signal. The AC-coupling capacitor allows the amplifier
to bias the signal to an optimum DC level. Assuming
zero-source impedance, the -3dB point of the highpass
filter is given by:
Gain Selection
Table 2 shows the suggested gain settings to attain a
maximum output power from a given peak input voltage
and given load.
1
f
=
-
3dB
Output Offset
Unlike a class AB amplifier, the output offset voltage of
class D amplifiers does not noticeably increase quies-
cent current draw when a load is applied. This is due to
the power conversion of the class D amplifier. For
example, an 8mV DC offset across an 8Ω load results
in 1mA extra current consumption in a class AB device.
In the class D case, an 8mV offset into 8Ω equates
to an additional power drain of 8µW. Due to the high
efficiency of the class D amplifier, this represents an
2πR C
IN IN
Choose C so f
is well below the lowest frequency
-3dB
IN
-3dB
of interest. Setting f
too high affects the low-fre-
quency response of the amplifier. Use capacitors
whose dielectrics have low-voltage coefficients, such
as tantalum or aluminum electrolytic. Capacitors with
high-voltage coefficients, such as ceramics, may result
in increased distortion at low frequencies.
Charge-Pump Capacitor Selection
Use capacitors with an ESR less than 100mΩ for opti-
mum performance. Low-ESR ceramic capacitors mini-
mize the output resistance of the charge pump. For
best performance over the extended temperature
range, select capacitors with an X7R dielectric.
additional quiescent current draw of: 8µW/(V /100 ♦ η),
which is on the order of a few microamps.
DD
Input Amplifier
Differential Input
The MAX9713/MAX9714 feature a differential input struc-
ture, making them compatible with many CODECs, and
offering improved noise immunity over a single-ended
input amplifier. In devices such as PCs, noisy digital sig-
nals can be picked up by the amplifier’s input traces.
The signals appear at the amplifiers’ inputs as common-
mode noise. A differential input amplifier amplifies the
Flying Capacitor (C1)
The value of the flying capacitor (C1) affects the load
regulation and output resistance of the charge pump. A
C1 value that is too small degrades the device’s ability to
provide sufficient current drive. Increasing the value of
C1 improves load regulation and reduces the charge-
pump output resistance to an extent. Above 1µF, the on-
10 ______________________________________________________________________________________
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers
resistance of the switches and the ESR of C1 and C2
dominate.
Sharing Input Sources
In certain systems, a single audio source can be shared
by multiple devices (speaker and headphone ampli-
fiers). When sharing inputs, it is common to mute the
unused device, rather than completely shutting it down,
preventing the unused device inputs from distorting the
input signal. Mute the MAX9713/MAX9714 by driving SS
low through an open-drain output or MOSFET (see the
System Diagram). Driving SS low turns off the class D
output stage, but does not affect the input bias levels of
the MAX9713/MAX9714. Be aware that during normal
operation, the voltage at SS can be up to 7V, depending
on the MAX9713/MAX9714 supply.
Output Capacitor (C2)
The output capacitor value and ESR directly affect the
ripple at CHOLD. Increasing C2 reduces output ripple.
Likewise, decreasing the ESR of C2 reduces both rip-
ple and output resistance. Lower capacitance values
can be used in systems with low maximum output
power levels.
Output Filter
The MAX9713/MAX9714 do not require an output filter.
The device passes FCC emissions standards with
36cm of unshielded speaker cables. However, output
filtering can be used if a design is failing radiated emis-
sions due to board layout or cable length, or the circuit
is near EMI-sensitive devices. Use a ferrite bead filter
when radiated frequencies above 10MHz are of con-
cern. Use an LC filter when radiated frequencies below
10MHz are of concern, or when long leads connect the
amplifier to the speaker. Refer to the MAX9714
Evaluation Kit schematic for details of this filter.
Supply Bypassing/Layout
Proper power-supply bypassing ensures low distortion
operation. For optimum performance, bypass V
to
DD
PGND with a 0.1µF capacitor as close to each V
pin
DD
as possible. A low-impedance, high-current power-sup-
ply connection to V is assumed. Additional bulk
DD
capacitance should be added as required depending on
the application and power-supply characteristics. AGND
and PGND should be star connected to system ground.
Refer to the MAX9714 Evaluation Kit for layout guidance.
Pin Configurations
TOP VIEW
PGND
PGND
1
2
3
4
5
6
7
8
24 PGND
23 PGND
PGND
PGND
1
2
3
4
5
6
7
8
24 PGND
23 PGND
V
22
21
V
V
V
22
21
V
V
DD
DD
DD
DD
DD
DD
V
V
DD
DD
MAX9714
MAX9713
C1N
C1P
20 FS2
19 FS1
18 G2
17 G1
C1N
C1P
20 N.C.
19 FS2
18 FS1
17 N.C.
CHOLD
N.C.
CHOLD
N.C.
TQFN (7mm x 7mm)
TQFN (5mm x 5mm)
Chip Information
MAX9713 TRANSISTOR COUNT: 3093
MAX9714 TRANSISTOR COUNT: 4630
PROCESS: BiCMOS
______________________________________________________________________________________ 11
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers
Functional Diagrams
10V TO +25V
100µF
0.1µF
0.1µF
1
2
3
4
21 22
23 24
PGND
PGND
V
V
DD
DD
0.47µF
0.47µF
12 IN+
OUT+ 30
OUT+
29
OUT- 28
MODULATOR
OSCILLATOR
H-BRIDGE
11
IN-
27
OUT-
18
19
FS1
FS2
V
REG
V
REG
14
SHDN
V
IH
MAX9713
GAIN
CONTROL
15 G1
16 G2
13 SS
V
V
REG
REG
6
5
C1P
C1N
SHUTDOWN
CONTROL
C1
0.1µF
CHARGE PUMP
CHOLD
REG
9
0.18µF
0.47µF
10 AGND
7
C2
1µF
LOGIC INPUTS SHOWN FOR A = 16dB (SSM).
V
V
DD
12 ______________________________________________________________________________________
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers
Functional Diagrams (continued)
10V TO +25V
100µF
0.1µF
0.1µF
1
2
3
4
21 22
23 24
PGND
PGND
V
V
DD
DD
0.47µF
0.47µF
10 INL+
OUTL+ 32
OUTL+
31
OUTL- 30
29
MODULATOR
H-BRIDGE
9
INL-
OUTL-
19
20
FS1
FS2
V
V
REG
REG
OSCILLATOR
MODULATOR
0.47µF
0.47µF
15 INR+
OUTR+ 26
OUTR+
25
OUTR- 28
H-BRIDGE
16
INR-
27
OUTR-
11
SHDN
V
IH
GAIN
CONTROL
17 G1
18 G2
12 SS
V
REG
V
REG
MAX9714
6
5
C1P
C1N
SHUTDOWN
CONTROL
C1
0.1µF
CHARGE PUMP
REG
14
0.18µF
0.47µF
13 AGND
CHOLD
7
C2
1µF
LOGIC INPUTS SHOWN FOR A = 16dB (SSM).
V
V
DD
______________________________________________________________________________________ 13
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers
System Diagram
V
DD
1µF
SHDN
OUTL-
V
DD
0.47µF
0.47µF
INL-
INL+
OUTL+
CODEC
MAX9714
0.47µF
0.47µF
INR+
OUTR+
INR-
SS
OUTR-
5V
1µF
100kΩ
0.18µF
SHDN
1µF
V
DD
INL-
1µF
1µF
15kΩ
15kΩ
MAX9722B
OUTL
INL+
INR+
OUTR
1µF
PV
SV
SS
INR-
SS
1µF
C1P
CIN
30kΩ
30kΩ
1µF
LOGIC INPUTS SHOWN FOR A = 16dB (SSM)
V
14 ______________________________________________________________________________________
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
D2
D
C
L
b
D2/2
D/2
k
E/2
E2/2
C
(NE-1) X
e
E
E2
L
k
L
DETAIL A
e
(ND-1) X
e
DETAIL B
e
C
C
L
L
L
L1
L
L
e
e
DALLAS
SEMICONDUCTOR
A
A1
A2
PROPRIETARYINFORMATION
TITLE:
PACKAGE OUTLINE
32, 44, 48, 56L THIN QFN, 7x7x0.8mm
APPROVAL
DOCUMENT CONTROL NO.
REV.
1
21-0144
D
2
______________________________________________________________________________________ 15
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
DALLAS
SEMICONDUCTOR
PROPRIETARYINFORMATION
TITLE:
PACKAGE OUTLINE
32, 44, 48, 56L THIN QFN, 7x7x0.8mm
APPROVAL
DOCUMENT CONTROL NO.
REV.
2
21-0144
D
2
16 ______________________________________________________________________________________
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
D2
0.15
C A
D
b
0.10 M
C A B
C
L
D2/2
D/2
k
0.15
C
B
MARKING
XXXXX
E/2
E2/2
C
L
(NE-1) X
e
E2
E
k
L
DETAIL A
e
PIN # 1
I.D.
PIN # 1 I.D.
0.35x45∞
(ND-1) X
e
DETAIL B
e
L
C
C
L
L1
L
L
L
e
e
0.10
C
A
0.08
C
C
A3
A1
PACKAGE OUTLINE,
16, 20, 28, 32L THIN QFN, 5x5x0.8mm
1
-DRAWING NOT TO SCALE-
21-0140
F
2
______________________________________________________________________________________ 17
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
COMMON DIMENSIONS
20L 5x5 28L 5x5
EXPOSED PAD VARIATIONS
D2 E2
DOWN
BONDS
ALLOWED
L
PKG.
SYMBOL MIN. NOM. MAX. MIN. NOM. MAX. MIN. NOM. MAX. MIN. NOM. MAX.
16L 5x5
32L 5x5
PKG.
CODES
MIN. NOM. MAX. MIN. NOM. MAX. ±0.15
T1655-1
T1655-2
3.00 3.10 3.20 3.00 3.10 3.20
3.00 3.10 3.20 3.00 3.10 3.20
NO
YES
NO
A
**
**
**
**
0.70 0.75 0.80 0.70 0.75 0.80 0.70 0.75 0.80 0.70 0.75 0.80
0.02 0.05 0.02 0.05 0.02 0.05 0.02 0.05
0.20 REF. 0.20 REF. 0.20 REF. 0.20 REF.
A1
0
0
0
0
T1655N-1 3.00 3.10 3.20 3.00 3.10 3.20
A3
b
T2055-2
T2055-3
T2055-4
T2055-5
3.00 3.10 3.20 3.00 3.10 3.20
3.00 3.10 3.20 3.00 3.10 3.20
3.00 3.10 3.20 3.00 3.10 3.20
NO
YES
NO
Y
0.25 0.30 0.35 0.25 0.30 0.35 0.20 0.25 0.30 0.20 0.25 0.30
4.90 5.00 5.10 4.90 5.00 5.10 4.90 5.00 5.10 4.90 5.00 5.10
4.90 5.00 5.10 4.90 5.00 5.10 4.90 5.00 5.10 4.90 5.00 5.10
**
**
D
E
3.15 3.25 3.35 3.15 3.25 3.35 0.40
e
0.80 BSC.
0.25
0.30 0.40 0.50 0.45 0.55 0.65 0.45 0.55 0.65 0.30 0.40 0.50
0.65 BSC.
0.50 BSC.
0.50 BSC.
T2855-1
T2855-2
3.15 3.25 3.35 3.15 3.25 3.35
2.60 2.70 2.80 2.60 2.70 2.80
NO
NO
**
**
**
**
k
-
-
0.25
-
-
0.25
-
-
0.25
-
-
L
T2855-3
T2855-4
3.15 3.25 3.35 3.15 3.25 3.35
2.60 2.70 2.80 2.60 2.70 2.80
2.60 2.70 2.80 2.60 2.70 2.80
3.15 3.25 3.35 3.15 3.25 3.35
YES
YES
NO
L1
-
-
-
-
-
-
-
-
-
-
-
-
N
ND
16
4
20
5
28
7
32
8
T2855-5
T2855-6
T2855-7
T2855-8
**
**
**
NO
YES
4
5
7
8
NE
2.80
3.35
3.35
3.20
2.60 2.70
3.15 3.25
2.60 2.70 2.80
3.15 3.25 3.35
3.15 3.25 3.35
3.00 3.10 3.20
WHHB
WHHC
WHHD-1
WHHD-2
JEDEC
0.40
Y
N
NO
T2855N-1 3.15 3.25
**
**
**
NOTES:
T3255-2
T3255-3
T3255-4
3.00 3.10
1. DIMENSIONING & TOLERANCING CONFORM TO ASME Y14.5M-1994.
2. ALL DIMENSIONS ARE IN MILLIMETERS. ANGLES ARE IN DEGREES.
3. N IS THE TOTAL NUMBER OF TERMINALS.
3.00 3.10 3.20 3.00 3.10 3.20
3.00 3.10 3.20 3.00 3.10 3.20
YES
NO
**
**
NO
T3255N-1 3.00 3.10 3.20 3.00 3.10 3.20
4. THE TERMINAL #1 IDENTIFIER AND TERMINAL NUMBERING CONVENTION SHALL
CONFORM TO JESD 95-1 SPP-012. DETAILS OF TERMINAL #1 IDENTIFIER ARE
OPTIONAL, BUT MUST BE LOCATED WITHIN THE ZONE INDICATED. THE TERMINAL #1
IDENTIFIER MAY BE EITHER A MOLD OR MARKED FEATURE.
**SEE COMMON DIMENSIONS TABLE
5. DIMENSION b APPLIES TO METALLIZED TERMINAL AND IS MEASURED BETWEEN 0.25 mm AND 0.30 mm
FROM TERMINAL TIP.
6. ND AND NE REFER TO THE NUMBER OF TERMINALS ON EACH D AND E SIDE RESPECTIVELY.
7. DEPOPULATION IS POSSIBLE IN A SYMMETRICAL FASHION.
8. COPLANARITY APPLIES TO THE EXPOSED HEAT SINK SLUG AS WELL AS THE TERMINALS.
9. DRAWING CONFORMS TO JEDEC MO220, EXCEPT EXPOSED PAD DIMENSION FOR T2855-1,
T2855-3 AND T2855-6.
10. WARPAGE SHALL NOT EXCEED 0.10 mm.
11. MARKING IS FOR PACKAGE ORIENTATION REFERENCE ONLY.
12. NUMBER OF LEADS SHOWN ARE FOR REFERENCE ONLY.
PACKAGE OUTLINE,
16, 20, 28, 32L THIN QFN, 5x5x0.8mm
2
-DRAWING NOT TO SCALE-
21-0140
F
2
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
18 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2004 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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